New World Record for Solar Cell Technology

The US Department of Energy announced on Tuesday that a project it funded had set a new world's record for solar cell efficiency. According to DOE's press release,

...with DOE funding, a concentrator solar cell produced by Boeing-Spectrolab has recently achieved a world-record conversion efficiency of 40.7 percent, establishing a new milestone in sunlight-to-electricity performance. This breakthrough may lead to systems with an installation cost of only $3 per watt, producing electricity at a cost of 8-10 cents per kilowatt/hour, making solar electricity a more cost-competitive and integral part of our nation’s energy mix.

Let's give this some context:

According to the National Renewable Energy Laboratory's Power Technologies Energy Data Book, Fourth Edition, concentrator solar technologies "...produce electricity at solar-to-electric efficiencies for the system of up to 30%." In the best case scenario for cells used with this technology, the Data Book reports efficiencies of 27-39%, with pre-commercial models averaging 15-24%.

A post at Slashdot points to a German site that shows where to best place solar sites for matching the world's energy consumption (2003 figures) based on an 8% efficiency rate. The Slashdot writer notes "At 40% efficiency, it looks like a square 265 miles on a side in the American southwest would do it.